Bow saw

ABSTRACT

A bow saw provided with a handle on the rear end of its bow-shaped frame can be coupled to a rod (32), for instance a telescopic rod, by a rod-attachment coupling. For this purpose, the rear section of the bow-shaped frame (10) has a detent element (34) which is welded on it which is surrounded by the handle shell (30) of the handle and a device insertion pin (36) which is swingably fastened on the frame (10) by fork arms (38) in the region of the detent element (34). This device insertion pin (36) can be form-locked to the detent element (34) in the outward-swung position of the handle so that the device insertion pin (36) protrudes towards the rear and a rod (32) provided with a corresponding insertion hole and a coupling can be pushed onto it. The movement of the device insertion pin (36) into the coupling position is effected by entrainment upon the swinging of the handle shell (30). When the rod is attached via the rod fastening coupling to the bow saw, even distant branches or the like can be cut, but in the uncoupled condition the coupling device does not prevent actuation of the saw when the handle shell is in its inward-swung position.

The present invention relates to a tree saw developed as a bow saw. Suchbow saws are available in two variants. The one variant, which is known,for instance, as the Dithmarsch form, has on the rear section of theframe an ergonomically favorably shaped handle by which the saw can begrasped and conveniently operated provided that the branches or otherparts to be sawed are near the handle.

If more distant objects, for instance branches which are high up or at adistance away are to be sawed off, saws to which an extension rod can beconnected, for instance a telescopic rod, are used. There are saw bladesto which either a handle or a rod can be attached via a suitablecoupling. For tree saws which are developed as bow saws, the bow-shapedframe has been provided with a cylindrical or conical socket into whichan extension rod can be inserted. The handling of such a saw or rod is,however, difficult and unfavorable since a conveniently accessiblehandle is not present and the saw must be grasped on the frame and/or onthe socket.

The object of the present invention is therefore to provide a tree sawwhich is developed as a bow saw and can be used optionally with thecustomary ergonomically favorably shaped handle or with an extension rodin order to saw off objects lying at a greater distance away.

This object is achieved by the features set forth in claim 1, takentogether. By the arrangement in accordance with the invention of thecoupling place on the end of the bow-shaped frame the result is obtainedthat its presence is not noted and the handling of the saw cannot beimpaired since those coupling parts lie embedded within the handle whenthe saw is operated directly by one's hand. By the swinging-away of ahandle piece, which is preferably developed as a handle shell, thecoupling elements provided on the saw are, in accordance with onesuitable embodiment of the invention, automatically brought into theiractive position so that after an extension rod has been pushed on adevice insertion pin forming the coupling element of the saw, the saw isimmediately ready for use.

As rod-attachment coupling, there is preferably used a rod-attachmentcoupling in accordance with Federal Republic of Germany 31 30 703 C2,but other rod-attachment couplings can also be used, including oneswhich are already available on the market, provided that they have acoupling element which corresponds to the device insertion pin (or itsmating piece) and is swingably pivoted on the bow-shaped frame in such amanner that it is covered by the handle when not in use and which, incoupled position, can be form-locked in one or more positions.

Various developments of the invention can be noted from the dependentclaims.

One embodiment of the invention will be described below with referenceto the drawing, in which:

FIG. 1 is a side view of a bow saw developed in accordance with theinvention, with the handle in inward-swung position, the handle beingshown broken open so that the inward-swung device insertion pin isvisible;

FIG. 2 shows the bow saw of FIG. 1 with a rod attached via arod-attachment coupling on the end of the frame;

FIG. 3 shows a side elevation view of the fastening and mounting of thedevice insertion pin on the end of the frame;

FIG. 4 is a top view thereof;

FIG. 5 is a front view of a safety disk on FIG. 4;

FIG. 6 is a section at 6-6 in FIG. 4; and

FIG. 7 is a side elevation view of a detent member in FIG. 3.

FIG. 1 shows a bow saw of the so-called Dithmarsch type developed astree saw, such as used in orchards, gardens and vineyards, as well as inthe field of construction, by homeowners and the like.

The saw has a bow-shaped frame 10 which bears on its front end a frontreceiving mounting 12 for the saw blade 14. The rear receiving mounting16 for the saw blade is arranged in a short lever arm 18 of a tensioninglever 20 which is pivoted via a pivot pin 22 on the rear end of theframe and which is adapted in shape to the rear section of the frame 10.The tensioning lever 20 is secured in the tensioned position by a togglelever 24 which is pivoted on the frame 10 by means of a pivot pin 26, ascan be noted from FIGS. 1 and 2. By means of another pivot pin 28, ahandle shell 30 forming the handle is pivoted on the frame 10, the shellso surrounding the rear section of the frame 10 in its inward-swungposition (FIG. 1) that the bow saw can be grasped in ergonomicallyfavorable manner when the handle is closed (FIG. 1). The handle shell 30can be swung out around the pivot pin 28 into the position shown in FIG.2, in which a rod 32 can be fastened in the manner described below via arod-attachment coupling to the frame 10 so that the saw can be guided bymeans of the rod in order to cut branches located at a height or adistance away. Both in the inwardswung position shown in FIG. 1 and inthe outward-swung position shown in FIG. 2, the toggle lever 24 can beactuated in order to release or lock the tensioning lever 20, so that inboth of the positions shown in FIG. 1 and FIG. 2, the saw blade can beturned around the clamping axis or can be replaced by a new one when ithas become worn.

The rod-attachment coupling which creates the connection between the rod32 and the rear end of the frame is advisedly developed in the mannerdescribed in Federal Republic of Germany 31 30 703 C2. However, theinvention is not limited to this type of rod-attachment coupling, andother couplings which permit a separating of bow saw and rod can also beused. One requirement is that the handle, i.e. the handle shell 30, can,when the rod is removed, assume the normal position shown in FIG. 1 inwhich the saw can be handled in an ergonomically favorable manner.

In the central section of the rear frame, a detent element 34 ofrectangular cross section is welded-on, it being most clear in thedifferent showings in FIGS. 3-6. A device insertion pin 36 is developedin the form of a fork and its fork arms 38 surround the rear section ofthe bow-shaped frame 10 and the detent element 34, where it is swingablypivoted via a pivot pin 40. The pivot pin 40 is located in the frontextension of the middle axis of the detent element 34 and thearrangement is such that the device insertion pin 36 is so swung in theposition shown in FIG. 1 that it is surrounded by the handle shell anddoes not interfere with the handling of the handle. The device insertionpin 36 has a locking hole 42 into which a coupling leaf spring 44 canengage by a latch, which is built in the rod 32 and can be unlocked by abutton 46. As can be noted from FIG. 2, in coupled position the button46 lies protected within the handle shell 30 so that it cannot beunintentionally loosened by branches or the like. As can furthermore benoted from FIG. 2, the rod 32 passes through the handle shell in apassage hole 48 and the button 46 can be unlocked through a recess 50 inthe handle shell in the position shown in FIG. 2.

The form-locked connection between rod 32 and detent element 34 or frame10 is produced in the following manner.

A sleeve 52 which is adapted at its rear end to the front end of the rod32 is pushed over the device insertion pin 36. This sleeve 52 surroundsa safety or locking disk 54 which has two guide holes 56 which travel onthe fork arms 38 (FIG. 5) whereby the sleeve 52 is prevented fromdropping off from the device insertion pin 36. The fork arms 38 of thedevice insertion pin 36, as can be noted from FIGS. 3 and 4 surround thedetent element 34 (FIG. 7), which has a rectangular locking projection58 which faces the rod 32, and engages, in the position shown in FIGS. 2and 3, into the rectangular recess 60 in a cap disk 62 which isdisplaceable on the device insertion pin 36 together with the sleeve 52and the locking disk 54. A plate spring 64 or leaf spring is providedbetween the locking disk 54 and the cap disk 62 in order to take uptolerances. In order to fasten a rod 32 by the rod attachment couplingto the bow saw, the handle shell 30 is swung around the pivot pin 28 outof the position shown in FIG. 1 into the position shown in FIG. 2. Uponthis swinging movement, the device insertion pin 36 is automaticallyswung about its pivot pin 40, since its end is carried along via thepassage hole 48 of the handle shell or a corresponding inner projectionof the handle shell 30. In this position, shown in FIG. 2, the rod 32can be pushed through the hole 40 in the shell 30, the front end of therod 32 provided with a device insertion hole and pressing against thesleeve 52 and the device insertion pin 36 and thus preventing the rod 32from swinging around the pin 40 since the cap disk 62 holds the forkarms 38 fast against the locking extension 58 of the detent element 34.

This locking is produced automatically when the rod 32 is pushed ontothe device insertion pin 36.

After the unlocking of the coupling by depressing the button 46, the rod32 can be removed from the device insertion pin 36 and the sleeve 52 canbe pulled back by hand together with the locking disk 54 and cap disk62, be pulled back by hand in order to open the lock between the disk 62and the locking projection 58. The handle shell 30 can then be broughtback into the position shown in FIG. 1, the device insertion pin 36being automatically carried along.

LIST OF REFERENCE NUMERALS

10 Bow-shaped frame

12 Mounting bearing

14 Saw blade

16 Read mounting bearing

18 Short lever arm

20 Tensioning lever

22 Pivot pin

24 Toggle lever

26 Pivot pin

28 Pivot pin

30 Handle shell

32 Rod

34 Detent element

36 Device insertion pin

38 Fork arms

40 Pivot pin

42 Hole

44 Coupling leaf spring

46 Button

48 Passage hole

50 Recess

52 Sleeve

54 Locking disk

56 Guide holes

58 Locking projection

60 Rectangular recess

62 Cap disk

64 Plate spring

I claim:
 1. A bow saw comprising:a bow-shaped frame having ends, a sawblade supported on the frame between the ends for being tensioned by theframe; the frame having an end region near one of the frame ends; ahandle swingably pivoted at a first pivot to the end region of theframe, the handle being shaped to cover over a portion of the end regionof the frame from the first pivot toward the one frame end; a pinswingably pivoted at a second pivot to the end region of the frame at aportion of the end region that is covered over by the handle when thehandle is pivoted toward the end region of the frame, and with the pinpivoted inwardly toward the end region of the frame, the handle gripsover the inwardly pivoted pin; the pin being swingable outwardly withreference to the end region of the frame, and locking elements forlocking the pin in an outwardly swung position.
 2. The bow saw of claim1, further comprising a device for the saw which is received on theoutwardly swung pin;the handle having a first end at the first pivot andhaving a section away from the first pivot; the handle section includinga portion thereof for receiving the device when the handle is swungoutward and the device is on the pin.
 3. The bow saw of claim 2, whereinthe device includes a rod that is received on the pin and the rod isreceived in the section of the handle.
 4. The bow saw of claim 3,further comprising an unlocking button in the section of the handle forunlocking the rod.
 5. The bow saw of claim 4, further comprising arecess at the section of the handle and the unlocking button isaccessible through the recess when the handle is pivoted to an outwardlyswung position.
 6. The bow saw of claim 2, wherein the pin has a forkshape including fork arms that straddle the end region of the frame, apivot pin connection at the second pivot between the fork arms and theend region of the frame.
 7. The bow saw of claim 2, wherein the pin hasa fork shape, including fork arms, a detent element placed on the endregion of the frame, a pivot pin connection at the second pivot betweenthe fork arms and the detent element.
 8. The bow saw of claim 7, whereinthe device includes a rod that is received on the pin and the rod isreceived in the section of the handle;the detent element including alocking projection; a sleeve around the pin and around the fork armsthereof for defining a stop for the rod placed on the pin; a cap disklocated on the pin and also around the fork arms and being displaceabletogether with the sleeve, the cap disk having a locking position wherethe cap disk surrounds the fork arms and the locking projectionextending from the detent element inside the sleeve.
 9. The bow saw ofclaim 8, further comprising a third pivot coupling between the pin andthe handle away from the first and second pivots of the handle and thepin, such that upon swinging out of the handle, the pin is alsoswung-out; and wherein the sleeve and the cap disk are automaticallybrought into a locking position when the rod is placed on the pin. 10.The bow saw of claim 8, further comprising a locking disk within thesleeve, the locking disk including holes therethrough which receive thefork arms and the locking disk is slidable on the fork arms; the lockingdisk including a portion between the holes thereof which defines a stoplimitation at the base of the fork arms.
 11. The bow saw of claim 10,further comprising a play equalization spring between the locking diskand the cap disk.
 12. The bow saw of claim 1, further comprising a thirdpivot coupling between the pin and the handle away from the first andsecond pivots of the handle and the pin, such that upon swinging out ofthe handle, the pin is also swung-out.
 13. The bow saw of claim 1,further comprising a tensioning lever on the bow-shaped frame fortensioning the saw blade between the ends of the frame; a toggle leverfor fastening the tensioning lever on the frame, wherein the togglelever and the tensioning lever are freely actuatable in every swingposition of the handle.